Vascular stenosis, an abnormal narrowing in a blood vessel or other tubular organ or structure, is a major health problem around the globe. Stenosis is most frequently found to affect coronary blood vessels. It results in partial or complete obstruction of blood flow in a coronary artery, as by a thrombus or a progressive buildup of atherosclerotic plaque and leads to major cardiovascular diseases that remain a leading cause of death.
As a result of occlusion caused by stenosis, blood flow in the blood vessel is diminished. When occlusion occurs in coronary blood vessels, for example the coronary artery, blood flow to the heart muscles is decreased causing ischemia induced angina and in severe cases myocardial infarcts and death. Insertion of stents in occluded blood vessels has been a substantially successful procedure for treating stenosis. As a common practice, a stent is deployed after patency has been restored in the occluded blood vessel. The deployed stent remains implanted to prevent a newly opened blood vessel from constricting spontaneously.
Stent selection is a critical factor in the successful maintenance of blood flow through the blood vessels. Stent are manufactured from different materials and have different structural designs and thus different stents have different flexibilities or radial stiffness.
The selection of a suitable stent is important because when a rigid stent is placed in a highly oscillating vessel the adjoining walls of the blood vessel experience friction from the rigid stent and thereby get injured. The injury to the blood vessel wall triggers physiological response such as thrombosis which is often followed by an inflammatory immune response finally leading to restenosis. On the other hand flexible stents are expensive to manufacture owing to high quality materials required for their manufacturing and intricate fabrication processes due to highly complex structural designs, and thus placing a flexible stent in a rigid vessel results in increased costs.
Therefore, it is desirable to develop a technique of selecting a stent that accounts for stress experienced by a blood vessel in which the stent is to be inserted. The technique is desirable to be simple and non-invasive.